object ScalaTypeDemo02 {
  def main(args:Array[String]):Unit={
    var num1=1.2
    var num2=1.7f
    num2=num2.toFloat
    println(num2)

    println(num2.isInstanceOf[Double])
    println(num2.isInstanceOf[Float])
    println(sayHello)
  }
  def sayHello:Nothing={
    throw  new Exception("抛出异常")
  }
}
